re2c is a tool for writing very fast and very flexible scanners. Unlike
any other such tool, re2c focuses on generating high efficient code for
regular expression matching. As a result this allows a much broader
range of use than any traditional lexer offers. And last but not least
re2c generates warning free code that is equal to hand-written code in
terms of size, speed and quality.
 
It is released under Public Domain.
